PFS is one of the most reliable clearing houses out there and the majority of retail brokerges clear through them. As for MB trading, I can only speak about stocks. Their executions are lightning fast and customer service is excellent. Their software is ordinary(bereft of any bells and whistles) and is meant to be integrated with packages like e-signal. Their commissions are slightly on the higher side but IMO you will more than make up the difference by the speed of MB's executions. If there is one thing that stands out about this firm it is their executon speed.
